I don't know that this will directly answer your question but I've seen whole words spelled out in the waterfall. One would never tell that from the spectrum display but clearly in the waterfall there were words. In the top waterfall above, it does look like something of a video interference pattern.

You can transmit a pattern that causes the waterfall to show your callsign or the mode that you're using with fldigi... the mode thing can be cute if you're using an obscure mode. I don't use it, personally, but I see how it might be useful. I guess.

Yes I do know what it is, unfortunately. I operate in purely portable fashion and as such everything runs on a car battery, including the 19V DC to DC adapters that power my laptop. That is what you see there. That garbage sweeps the entire band in an upwards direction non-stop. And now I have TWO laptops with these adapters and a Gigabit switch that are all making noise of one sort or another. I am planning on putting all of those components into an ammo can (with ferrites as well) to try to mitigate all of that.

Looking at his first graphic, I see two other signals that don't have that cross-hatch problem. That station probably has a lot of noise on that antenna as well. The graphic below shows me switching antennas on the same frequency. The TOP antenna has a LOT of signals every 10 KC and NOISE. The other antennas don't see any of that. I have a common mode filter on order to cure that one antenna.

The patterns are a propagation effect. The patterns you get depend a lot on which band you're on (higher bands generally show less effect) and the propagation distance (more effect the farther away you are). They show up most clearly when you're looking at a broad, flat spectrum digital signal like digital voice.

Technically, the ionosphere's electrons (which reflect RF and enable long distance skip) have density irregularities -- they are more or less bunched up in "clouds", and each cloud acts as a separate reflector. The pattern you see represents "beats" (interference) between the different reflection paths. It changes with time because the clouds are moving around. You can call it "multipath interference", "selective fading" or "scintillation".

I think this is part of my fascination with SDR is that I never before had a radio that could even display a pan, not to mention a waterfall. The add-on's for those were expensive.

When I look at various bands I see all kinds of stuff going on. Some is easily recognizable as a human signal other stuff is man-made noise and then there is this other stuff that dances around, perhaps runs up and down the band.

I'm sure it existed when I had my old Kenwood and all the radios before that. I could just never see it. I do remember what I used to call "birdies" when I would tune my radio and suddenly hear this constant whistle. I could never figure out if the radio caused them or something else. Now I can see them!

We humans for the most part are visual beings. Being able to see a representation of our RF spectrum has made radio even more fun for me. I'm not transmitting as much and in fact I get great pleasure out of watching the wave forms of other transmissions.

I still have noise to find/hunt for and hopefully eliminate. It is new this winter. I didn't see it in summer. That massive peak just below 14.010 will move. Most of the time it sits right on 14.030 and as you can see there is some activity there right now that when the peak is in place over that frequency is just hidden.

So I'm finding having SDR to be fascinating to look at all these displays and signals.

I've been staring at the SDR displays for over 10 years now and really can't imagine ham radio any other way...honestly.

No joke.

I was first licensed 10 years ago (OK, so I'm a late bloomer). After a very brief stint with a couple of Kenwood rigs, I got an SDR-1000. It's was the first HF radio I did any ﻿serious HF with.

After that is was a 1500 and now I've been using a 6500 for a while.

While I've been a SWL for many years, and I theoretically understand how to play (HF) radio with a dial, I have never done so without using a panadapter. It's all I've ever really used, and it's all I know how to use. It's kind of... embarrassing, really. I'm pretty much lost when I can't see the band to pick out a station or an opening.

True story: I remember visiting W1AW a few years back. They offered to let me operate for a while. I had to decline... because all they had were radios with knobs!

I started radio in the early 1970's. I had a crystal 25w CW transmitter and I spent a month trying to build a receiver but I kept blowing things up so my Dad got me a Kenwood R599. Great receiver but dials only of course.

I had 3 crystals and I'd tune to my crystal freq and if in use I'd wait. Meanwhile I'd tune up/down and I heard all these things but never had a clue what they looked like.

I've been through about 6 knob radios and took many noise things as I tuned around to be either radio artifacts, external noise or something atmospheric. But now that I can see them it is fascinating.

Peter, you deprived yourself of an awesome experience. Back in the mid 80s I drove N1CUZ out to Newington from Scituate RI, where we both lived. That, BTW, is the vintage 1700 white house listed on my qrz page. That was prior to computerized logging so we took turns logging for the other who was OP. Imagine calling cq from Afghanistan, that's what it was like. Stations appeared out of nowhere, in an instant, there where hundreds of them. I can't speak for Bob, who I believe is SK now, but I couldn't write fast enough to stay ahead of him, when I was logging. Do it!

Panadapter do add a visual component to the process. For chasing dx, consider a simple listbox of calls in descending order by distance from your qth, independent of band. Upon selection, it would lock your rcv on his xmit and position your TX the appropriate offset plus clear freq. I think there are use cases where a pan might be superfluous.

My first was an hw-101, I had the pleasure to build myself. Both building and operating where hugely rewarding experiences.